Food Allergies Treatment

My youngest son (13 months) has a milk allergy, anything with a little bit of milk makes him sick. What do I feed him. Everything seems to have milk in it. Any ideas?

My baby is 9 weeks old. This week, she had diarrhea with blood in it, vomiting, and what looked like eczema. The doctor thinks it was just a GI infection. She is on Nutramigen right now and will switch back to her regular formula in a day or two to test if it was the infection or if it was a milk allergy. I’m just curious if this would be a typical onset of a milk allergy or not.